Emergence and transmission of influenza A viruses resistant to amantadine and rimantadine
Of the anti influenza virus drugs available, the M2 inhibitors have a longer history of use than NA inhibitors and include amantadine and rimantadine
. Amantadine's therapeutic antiviral spectrum is limited to influenza A virus.
Treatment of influenza: the therapeutic efficacy of rimantadine
HCI in naturally occurring influenza A2 outbreak.
Influenza Treatment with Antiviral Agents Dosing Recommendations * Due to seasonal influenza A (H1N1) resistance to oseltamivir, patients with suspected seasonal influenza A (H1N1) virus infection should be treated with zanamivir or alternatively with a combination of oseltamivir and an adamantane if zanamivir use is contraindicated (rimantadine
is preferred over amantadine because of an increased risk of adverse events associated with amantadine).
The recommended alternative to zanamivir in patients with laboratory evidence of influenza A, a negative test result, or no testing is the combination of oseltamivir plus rimantadine
The data also show that virus is resistant to amantadine and rimantadine
but the organism continues to remain susceptible to oseltamivir and zanamivir.
The CDC recommendation advised doctors to combine Tamiflu with rimantadine
(an older antiviral) or to substitute Tamiflu with Relenza (zanamivir), an antiviral that arrived on the market about 10 years ago.
The researchers examined the response of HCV to a panel of compounds including the well-known anti-viral drug, rimantadine
, which targets a similar protein in the flu virus.
However, four drugs have been approved to treat people who get the flu: amamadine (Symmetrel), rimantadine
(Flumadine), zanamivir (Relenza), and oseltamivir (Tamiflu).
This drug and its congener, rimantadine
(not available in South Africa), specifically inhibit the replication of influenza A viruses (they are ineffective against influenza B viruses) in low concentrations of about 0.03 - 1.0 [micro]g/ml.
FDA said beginning this summer, it is proposing to ban veterinarians from prescribing off-label, nonhuman uses of Tamiflu, amantadine and rimantadine
. The United States has been stockpiling drugs for a possible avianflu outbreak in humans.
Tom Jefferson and his colleagues from the Cochrane Vaccines Field examined evidence from trials on the efficacy of all four flu drugs: Tamiflu, Relenza, Amantadine, and Rimantadine
. They strongly warn against relying on drugs to stamp out a potential avian flu pandemic and believe complacency will deter the use of public-health measures, such as hygiene and isolation, to stop the spread of infection.